The zoo-produced, one-minute, 37-second video shows pregnant Rose-Tu, an 18-year-old Asian elephant, strolling back and forth across the room in the pachyderm barn that will serve as her maternity suite sometime in the coming days.

The calf she delivered in August 2008 ambles along at her side but she's separated from the other females in the herd. In the video, one of them reaches a trunk through the bars dividing them and stretches it toward Rose.

On Monday, the zoo delivered news that Rose-Tu's progesterone levels had fallen sharply, an indicator that labor would follow, perhaps within hours or up to a few days.

Rose delivered Samudra, her first calf, in August 2008, after more than 30 hours of labor.